Use the bvec_set_page and bvec_set_folio helpers to initialize bvecs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230203150634.3199647-17-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>